<?php

$arr01=["张三","李四","王五","赵六"];
$arr02=["username"=>"张三","password"=>"123","gender"=>"男","score"=>89];

//foreach(数组名称 as key =>value)
foreach($arr01 as $value){
  echo $value."<br>";
}

foreach($arr02 as $key=>$value){
  echo $key."=>".$value."<br>";
}